A double-side liquid crystal display device has been applied in a trading place such as a bank or a market due to a requirement of confirming a display on two opposite screens. In structure design of a double-side liquid crystal display device, two opposite liquid crystal panels share one set of backlight modules, according to a position relation between backlight and a light guide plate, the backlight modules are divided into two types—an edge-lighting type and a bottom-lighting type, the edge lighting type backlight module is widely applied due to benefits such as thinness.
Light provided by the backlight forms surface light after penetrating the light guide plate and becomes polarized light required by the liquid crystal panel after going through polarized sheets, the polarized sheets are attached to top and bottom sides of the liquid crystal panel respectively, which can increase costs of the attachment, and the polarized sheet consists of a polyvinyl alcohol (PVA) layer, a tri-cellulose acetate (TAC) layer and a polyethylene terephthalate (PET) film, whose structure is complicated, leading to a poor performance in light utilization of the polarized sheet. Moreover, the amount of light of a reflective surface and that of a light-emitting surface of the light guide plate are different, which make high brightness in the liquid crystal panel on a side of the light-emitting surface, and low brightness in the liquid crystal panel on a side of the reflective surface, brightness of the two liquid crystal panels corresponding to one backlight will be different, light utilization efficiency is low.